Visit each site and determine the physical and electrical
condition of each transducer. Document that information for future analysis.
Among the conditions that should be noted are:
| 1. |
The appearance of: |
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a. |
The cabling |
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damaged
or fouled |
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b. |
The transducer housing |
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fouled and extent and type of that fouling |
| 2. |
The performance of the transducer |
|
| |
a. |
Lift the unit from the liquid and note the output on its
indicator or using a handheld DVM. |
| |
b. |
Return the unit to its installed position and note the
output and its accuracy (i.e. measure the fluid level and compare it to the
output of the transducer note any deviation and its magnitude) |
| 3. |
Any other parameter that may be appropriate such as the
excitation voltage and an indication that the units performance is: |
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a. |
acceptable |
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b. |
marginal |
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c. |
unacceptable |
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* Be sure that the inspector notes why the device falls
into the evaluation category. |
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Visiting each site on a regular basis for the
purpose of this examination will provide trend information on which a more
appropriate schedule can be based. The initial evaluation interval should be
frequent until sufficient data has been accumulated. Although it may be
onerous, an examination interval of 1 month or less for a period of 6 months
would be a good starting point. After this initial evaluation has occurred
the data should be analyzed to determine:
|
| 1. |
The rate of fouling |
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| 2. |
The rate of change in performance of the measurement
parameters in the log sheets. |
| 3. |
Any degradation in performance indicated by the
technician. |
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* Degraded performance can point to the cause of failure
allowing the user to be proactive and avoid system downtime. |
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At this point a regular cleaning cycle can be
scheduled based on the observed rate of fouling and problematic sites can be
targeted for remedial action. The evaluation procedures should be maintained
although their period can be extended or reduced to maintain an accurate
picture of the system as a whole. |
return to KPSI Level and Pressure Transducer Application Notes
